Method of making light weight refractory brick



Patented Dec. 10, 1940 UNITED STATES PATENT OFFICE METHODOF MAKING LIGHTWEIGHT REFRACTORY BRICK Clarence Sylvester Matheny, Haydenville, Ohio,assignor to National Fireproofing Corporation, Pittsburgh, Pa., acorporation oi. Pennsylvania No Drawing. Application July 15, 1937,Serial No. 153,786

3 Claims.

This invention relates to improvements in light-weight refractoryinsulating brick or the 5 uct due to its knitting together with thevarious ingredients in the tempered batch.

The use of such shredded or comminuted paper is also very beneficial indrying because of the capillary action set up throughout the fibers ofthe material. This results in low loss in burnout material during thedrying period, which is directly attributable to the uniformity ofdrying. The paper fibers themselves also add great strength in the dryor drying state, and there is substantially no loss in drying due tocracks or breaking in handling, which is common when materials of anon-fibrous nature are used.

It is also found that the firing or burning of the bricks is materiallyaided by the use of shredded or comminuted paper because the ignition ofthe finely divided paper fibers begins at a much lower temperature,approximately 400 R, which is considerably below that of ordinaryburn-out materials. The finely divided fibers burn-out at this stage,opening the channels for the escape of the gases from the heavier orcoarser particles of bum-out materials which ignite later, thuspreventing disruption of the clay body. The use of shredded orcomminuted paper further results in a product of greater strength, asthe employment of paper allows for the use of much larger quantities ofwater in the tempered batch, yet allowing the tempered batch to bemolded satisfactorily. Since the water is the vehicle for the movementof the clay in the batch, additional water aids in bringing the clay inextremely intimate contact with the fibers and other combustibles. Thesubsequent tempering of the batch in a wet pan or other tempering ormixing machinery produces a knurly and fibrouslike structure, which isunattainable by the use of the more granular type burn-out materials,and because of this knurly structure, greater strength results in thefinished product.

Actual tests have demonstrated that paper is beneficial to burn-outbrick in amounts'ranging from five to fifty percent of the total batchwhen combined with peanut hulls, sawdust, round corn cobs, etc.

In an insulating brick suitable for service at 1600 F., 20% to 25%shredded or comminuted paper is found to be the most desirable; in aninsulating brick suitable for service at 2000 F., 25%

to gives the best results; and in an insulating brick suitable forservice at 2600" F., 20% to 25% seems to give the best results.

The resultant product possesses higher insulating value than brick madeonly with the more granular materials because the paper materials 15produce an excessive amount of fine cells. Heat travels in a wave motionand will penetrate into a new medium when it strikes a fiat surface, butwhen it strikes at an angle it is reflected; hence the excessiveporosity of the paper fired brick 20 produces a higher insulating value,there being a minimum of fiat surfaces.

While the invention has been described as for use in light-weightinsulating brick, it is obviously adapted for any fired clay product in25 which light-weight or insulating value or high porosity is desired.

I claim:

1. The method of making light-weight refractory insulating brick, whichcomprises mixing the subjecting it to a firing temperature in a kiln toburn-out the paper.

2. The method of making light-weight refractory insulating brick, whichcomprises mixing the batch material of clay with 20% to 25% shredded orcomminuted paper, tempering the batch in a 40 wet state to produce aknurly and fibrous structure, molding the batch to the desired shape,and subjecting it to a firing temperature in a kiln to burn-out thepaper.

3. The method of making light-weight refractory insulating brick, whichcomprises mixing the batch material of clay with 25% to 30% shredded orcomminuted paper, tempering the batch in a wet state to produce a knurlyand fibrous structure, molding the batch to the desired shape, and

subjecting it to a firing temperature in a kiln to burn-out the paper.

CLARENCE SYLVES'I'ER MATHENY.

